Oven burner ignition and control mechanism



Dec. 18, 1951 c. M. MAYER OVEN BURNER IGNITION AND CONTROL MECHANISM 3 Sheets-Sheet 1 Filed Dec.

' INVENTOR. (/rcza M Mayer BY #M Dec. 18, 1951 c. M. MAYER OVEN BURNER IGNITION AND CONTROL MECHANISM Filed Dec. 3 SheerLs-Sheet 5 INVENTOR.

Chas. f2 Mayer %MAQ7M Patented Dec. 18, 1951 MECHANI Charles M. Mayer Mansfield' ohim assi g nor to" The Tapp'an Stove Company, Mansfielctsflhio,

a corporation of: Ohio ApplicationDecember 11, I950; Serial No. 2002114 v6 Claims. 1

This invention relates to an automatic ignition and control mechanism for igniting and controllingthe operation of cooking range ovens, and is a modification of the mechanisms disclosed in the ccpending applications'of John M. Hoif and myself, Serial No". 1 53 664 and Serial No. 163,764, filed April 3-, 1'950'and May- 23; 1950, respectively. It is especially designed for use with a clocli actuated time control mechanism which automatically effects theturning on and off of the oven burner at predetermined s'ettimes, but is alsoarranged to be used-independently of the time control mechanism in which case the oven burner is manually turned on and on as desired.

The mechanism is-de'signe'd for use with a main gaseous fuel burner and includes 'a gaseous fuel pilot burner by which the main burner is ignited. The mechanism is so constructed and arranged that-the main burner is under the control of the pilot burner at all: times; The pilot burner-must be. ignited" in order for gas to be supplied tozthe maintburn'er Should the pilot burner be extinguished for any reason during operation the supply of gas to the main-burner will be promptly out 01f, and it cannot again be supplied until the pilot burner has been re-ignited. This arrangement provides a safety feature which prevents the accumulation of unburned gas in an oven which may violently explode when an attempt. is made to light either the main or pilot burnen It has been found by experience that both the main burner and the pilot burner in cooking range 'el'ement'by which the pilot burner is ignited, a

pair of normally open manually operable switches, a normally closed switch which is adapted to be opened by a thermostatic element mounted in position to be heated by the pilot burner, a clock operated switch and anelectric circuit which includes the aforesaid switches,

the electric ignition element and thesolenoid.

Themain control valve isa-standard: cut-off va-Ive having one closed or offposition and two open or on positions. Whenthis valve is turned one on position the mechanism is set for manual control of the cooking time-and when it -is turned to the 'other on position the cooking timeieautomatically controlled by the time control mechanism. In operationgaslilows from the supply manifoldithrou gh the-main control valve and intothesa-fetycontrol mechanism. From the safety control" mechanism the gas flows through one conduit tothe pilot burner and through anether conduit ta the-oven temperature control valveand from there tdthemain burner.

'Fhe safetycentrol' mechanism I comprises a 'casing having -a gas in'I'et port, a pair ofga's outlet ports, one to -the: pilot burner and one to the main'burner, apair-er valves and an electromagnetvwhichis energized 'by' a thermocouple which is mounted" imposition te -be heated by the -pilot burn'er. One of th'e valves isnormally closed-and is operative closed position -toout off the flow of gas to both the pilot burnei and the main burner and the other valve is normally openand is operative when in closed osition to out oi? the fiow areas to the mainburner while permittinggas-toncw tothe pilot" burner. 'The solenoid is operative" when energized to simultaneously close the normall'y open valve and to open"the"norma'lly closed valve; and the electromagn'etis'nperative when energized to maintain" the normally closed valve open'after the solenoid haspeen deenergized. The-two'normany open switches are operatively" associated withithe main control valve andarearran'ged to he closedby the opening of the" main control valve and'lto beiopened by theclosing ofthe valve. One of A the switches is. actuated .whenthe control" valve issturned toand from oneof its open positions vand: the.- other switch. is actuated when the control valve-isturned to and from the other of its open positions.

Todnitiate operation 0t the main burner under .manua'lzcontrol cf. the: cooking time, the main control valve is tur-nedz to'the properopen- -positionfwhicin closeslltne associated normally open .switcm The cl'osingfiof'thisi switch effects the energizationrof theselectric ignition element and thersclenoid. The solenoid then simultaneously closes thelnormallyrcpen valveinmhevsafety control! mechanism and v open'sszthe normally closed velvet can-then; flow toKthepilot burneribut it cannotlflow to theimain'. burner. I'he pilot burner is then 'ignited 'bytheelectricignitionelemerit and projects a :flame againstand: heats both the thermccoupleandthe: thermostatic: element; 'The: heating: outlive-"thermocouple generates a minute current of the order of .009 to .017 volt which energizes the electromagnet sufficiently for it to hold the normally closed valve in open position after the solenoid is de-energized, but not enough for the electromagnet to shift the normally closed valve from closed to open position. The heating of the thermostatic element will open the normally closed switch which will break the circuit to and de-energize the electric ignition element and the solenoid. The normally open valve of the safety control mechanism will then return to open position and the electromagnet will hold the normally closed valve open. Gas can then flow to the main burner where it is ignited by the pilot burner. The main burner will then operate under control of the oven temperature control valve as long as the main control valve is open and the pilot burner is ignited and heating the thermocouple and thermostatic element. If the pilot burner is extinguished for any reason during operation the thermocouple and the thermostatic element will immediately cool. The cooling of the thermocouple will de-energize the electromagnet which will release the normally closed valve which will then return to its closed position and cut off the flow of gas to both the pilot burner and the main burner. The cooling of the thermostatic element will close the normally closed switch will then effect re-energization of the solenoid and the electric ignition element. The solenoid will then open the normally closed valve and close the normally open valve, thus supplying gas to the pilot burner only. If the pilot burner is then re-ignited it will re-heat the thermostatic element and the thermocouple, thus re-initiating operation after which the mechanism will operate as described. To terminate operation the main control valve is manually closed.

For automatic operation I provide a clock actuated time control mechanism which may be set to initiate operation of the main burner at a predetermined set time and to terminate operation thereof at a predetermined set later time. The time control mechanism includes a, normally open switch which is in series with the thermostatically operated normally closed switch and one of normally open switches associated with the main control valve. For automatic operation the time control is set to initiate operation at the desired time and to terminate operation at the desired later time and then the main control valve is turned to the proper open or on position which closes the normally open switch associated therewith. At the set time the time control mechanism will automatically close its normally open switch which will effect energization of the solenoid and the electric ignition element after which the mechanism will function exactly the same as with manual control until time to terminate operation. To terminate. automatic. operation I provide a quinching circuit whichis hooked into the circuit between thev thermocouple and the electromagnet. In the quinching circuit is a normally open switch which .is adapted to be momentarily closed at a set time .by the time control mechanism. When this switch is closed it establishes the quinching circuit which then damps out the current flowing from the thermocouple to the electromagnet and de-energizes the electromagnet. The electromagnet then releases the normally closed switch of the safety control mechanism which returns to its closed position and cuts ofi the flow of gas to both the pilot 4 burner and the main burner, thus terminating operation.

The principal object of the invention is to provide an improved automatic ignition and control mechanism for igniting and controlling the operation of cooking range ovens.

Another object of the invention is to provide a control mechanism of the character described which may be used in conjunction with a clock actuated time control mechanism or independently thereof as desired.

Other and more limited objects of the invention will be apparent from the following specification and the accompanying drawings forming a part thereof wherein:

Fig. '1 is a diagrammatic layout illustrating my improved automatic ignition and control mechanism applied to a cooking range oven burner using gaseous fuel;

Fig. 2 is an enlarged central longitudinal vertical section through the safety control mechanism showing the various parts in the positions they assume when the oven burner is turned off;

Fig. 3 is a view similar to Fig. 2 showing the various parts. in the positions they are automatically moved to when the main control valve is first turned on to initiate the operation of the main oven burner;

Fig. 4 is a horizontal section, taken on the line 4-4 of Fig. 1; and

Fig. 5 is a wiring diagram of the mechanism.

Referring now to the drawings by reference characters, the numeral I indicates a gaseous fuel burner which is mounted in or in heating relation to a cooking range oven 2. Gaseous fuel is supplied to the burner I from a manifold M through a conduit 3. Interposed in the conduit 3 are a main control valve 4, a safety control mechanism generally indicated by the numeral 5, and an oven temperature control valve 6. The main control valve 4 is a cut-off valve of standard construction having one closed or off position and two open or on positions. In either of the open positions it permits the flow of gas from the manifold M to the burner I, and in the closed position it completely cuts off the flow of gas from the manifold M. In one open position of the main control valve II the mechanism is set for manual control and in the other open position the mechanism is set for automatic control. This valve is manually opened and closed by a handle I and a valve stem 8, and directly controls the operation of the entire apparatus in that it initiates the operation of the entire apparatus when it is turned to either of the on positions and terminates the operation when it is turned to the ofi position. From the main control valve 4 gas flows through a connector 9 to the safety control mechanism 5, to be described in detail hereinafter. From the safety control mechanism 5 the gas flows through a connector II], the oven temperature control valve 6 and the conduit 3 to the burner I. The oven temperature control valve 6 is operative to regulate the amount of gas flowing to the burner I in order to maintain the oven at any desired set temperature. The valve 6 -is set to any desired temperature by a handle I I having a pointer I 2' which cooperates with a graduated dial I3 carried by the valve 6. The valve 6 is controlled according to the temperature setting by a thermostatic element I4 which is mounted in the oven 2 and is connected to the valve 6 as shown at I5.

accepts The oven temperature control v-alve Bis ofstand ard well known construction. Consequently it is not shown in detail herein; There are many different constructions available, anyone of which will work equaly well herein. Gas is also supplied to a pilot burner I 6- through a branch conduit H which extends between the safety control mechanism and the pilot burner [6. The pilot burner IE is disposed adjacent one end of the main burner l in positiontoignite the burner i when gas is supplied thereto; An electrical ignition element it isoperativelyassociated-with the pilot burner It imposition toignite the pilot burner l6 when gas is supplied thereto. A thermostatic element !9 and a thermocouple are mounted in position to be heated-by a 'flame'from the pilot burner. The thermostatic element I 9 is operative to open and closea switch 2| which controls the energizatiorrof the electrical ignition element l8 and a solenoid 2 2 which when energized operates the safety control mechanism to supply gas to the pilot burner 15, as will be described in connection with the descriptionof the safety control mechanismand the operation of the whole apparatus. The thermocouple 29 when heated is operative to hold the safety 'control mechanism in condition to maintain the supply of gas to both the'pilot burner l 6 and'the main burner l, as will also be described in connection with the description of the-safety control mechanism and the operation of the apparatus.

A pair of normally open masterswitches 23 and 24 are operatively associated with thevalve stem 8 of the main control valved and are adapted to be closed and opened by the opening and closing of the valve 4. As the valve stem 8 is turned in a clockwise direction to set the valve in one open position the switch 23 is closed by a cam 25 on the valve stem '8 through a link 26; andwhen the valve stem 8 is rotated in a counterclockwise direction to set the valve 4- in its other open position, the switch 24 is closed by the cam 2-5through a link 21. Conversely when the valve 4 is turned from either open position to the closed position the closed switch 23 or 24 will be opened.

The construction of the safety control valve mechanism 5 and its connection to the solenoid 22 will now' be described, reference being had to Figs. 2, 3 and 4 of the drawing. This mechanism comprises a casing '35 having a chamber 36 in one end thereof and a chamber 3'! in the other end thereof. The chambers 36 and 31 are connected by a bore 38 of reduced diameter. A valve seat 39 is located at one end of the bore 38 and a similar valve seat 49 is located at the other end of the bore 38. The chamber 36 is closed by a removable cap 4l--and the chamber 31 is closed by a removable cap 42. A sleeve 43-, having end walls 4'4 and 45, is carried by the cap 4i and extends into the chamber 36. A valve stem 46 which is slidably mounted in a bushing 41 carried by the end wall 45 of the sleeve 43, extends from the chamber 35 into the sleeve 43. A valve disc d8 of suitable material is secured to one end of the valve stem 46 within the chamber 36, and a metal disc 49' is secured tov the other end of the stem 46. within the sleeve 43. A. spring 59 disposed about the valve stem 46 between the valve disc 48 and the end wall 45 .of the sleeve 43 normally-holds the valve disc 4'8v against the valve seat 39'. An electromagnetv 5| is secured to one end of a hollow exteriorly threaded stud 52 which extends out through aligned apertures in the end wall 4.4.,of the sleeve 43-, and in the end of the-cap 4!. 'A not: 53- screwed onto the outer portion of the stud-52 securely holds the magnet 5| and the sleeve 43 in -place. The legs of the electromagnet 51 have a winding 54 thereon, one end of which isconnected to a copper tube 28 which extends between the thermocouple 29' and the safety control 5, and the other end of which is connected to an insulated wire 29 withinthe tube 28. The tube 28 and the wire 29 therein establish an electric circuit between the thermocouple 20' and the winding 54 of the electromagnet 5|. The tube 28 is inserted into the hollow stud 52- and is held in place by a screw fitting 3|]. A sleeve 55- is screwed into a threaded recess in the end of-"the cap. 42, as indicated at 56, and extends into the chamber 37 a slight distance. One end of the sleeve 55 is closed by an end wall 51, and the other end which is open registers witha circular aperture 58 in the end wall of the cap 42. A plug 59- is slidably mounted in the sleeve 55 and extends out through the aperture 53 in the cap 42. The outer end of the plug 59 has a reduced extension 69 formed integral therewith, providing an annular shoulder 6! around the extension 69 at the outer end of the plug 59. A stem 62 which is secured to the inner end of the plug 59 extends out through an aperture 63 in the end wall 51 of the sleeve 55, and through the chamber 31 and into the-bore 38. The stem 52 has a collar 54 rigidly secured thereon between the end wall 5! and the outer end of the stem. A valve disc 65 of suitable material is slidably mounted upon-the stem 62 between the end wall 57 of the sleeve 55 and the collar 64. The valve disc 65 is adapted to engage the valve seat 40 to out oil the flow of gas into the chamber 31 during the initiation of operation, as will be hereinafter described. A compression spring 66-, disposed about the stem 52 between the end wall 51 and the valve disc 65, normally yieldingly holds the valve disc 55 against the collar 64. A compression spring 91 which is stronger than the spring 65 is disposed about the stem 62' within the sleeve 55 between the inner face of the end wall 51 and the inner end of the plug 59. The spring 61 is operative to return the plug 59, stem- 62 and valve disc 65 from the position shown in Fig. 3 back to their normal position as shown in Fig. 2, against the resistance of the spring 56. A port 68 in the casing 35 provides communication between the chamber 35 and the connector 9 to allow gas to flow from the main control valve 4' through the connector 9 and into the chamber 38. During normal operation of the main burner l gas flows from the chamber 36' through the reduced intermediate bore 38 and into the chamber 31. A port 69 which establishes communication between the conduit I! and the bore 38 is provided to supply gas to the pilot burner l9; and a port it establishes communication between the chamber 37 and the connector It! to permit the flow of gas from the chamber 31 to the main burner l through the oven temperature control valve 6 and the con-v duit 3.

The safety control valve mechanism 5is operatively connected to the solenoid 22 by a yoke 12 and a link 73. The yoke 12 which encompasses the safety control valve mechanism 5v as shown in Fig. 4 comprises a pair of spacedparallel arms 14 which are connected together at one end by a bridge 15. The bridge 15 has anapere ture 16 therein through which the reduced end 60 of the plug 59 extends with the inner face of thebridge engaging the shoulder 6| between the plug 59 and the reduced extension 60 thereof. The other ends of the arms 14 terminate in a pair of spaced parallel cars 11 to and between which one end of the link 13 is pivotally connected. The other end of the link 13 is pivotally connected to the movable core 18 of the solenoid 22 as indicated at 19.

In order to accommodate the mechanism for automatic control I provide a clock operated time control mechanism 89 of standard construction which comprises a clock 8| and a pair of normally open switches 82 and 83 which are adapted to be automatically closed and opened at predetermined times according to the setting of the clock 8|, which may be set as desired by the buttons 84 and 85. The switch 82 is disposed in series with the switches 24 and 2| and is operative when closed to initiate and maintain operation of the main burner I. The switch 83 is adapted to be momentarily closed simultaneously with the opening of the switch 82 and is operative when closed to terminate operation of the main burner I.

The operation of the apparatus independently of the time control mechanism will now be described in connection with Fig. 5. To initiate the operation of the oven burner I it is only necessary to set the oven temperature control valve 6 to the desired temperature and to manually turn the main control valve 4 clockwise from the off position to one on position. After that the ignition and operation of the burner are automatically controlled until the operation of the burner is terminated by manually turning the main control valve 4 from the on position to the off position. As the main control valve 4 is turned from the OE position to the on position the master switch 23 is closed by the cam 25 and link 26. After the main control valve has been opened gas can flow from the manifold M through the main control valve 4 and into the chamber 36 of the safety control valve mechanism 5, the various parts of which are in the position shown in Fig. 2. But the gas can go no farther since the valve disc 48 is being held against the valve seat 39 by the spring 56, thus closing the only exit from the chamber 36. As soon as the switch 23 is closed current flows from the positive side 81 of the line through the lead 88 to the switch 23. From the switch 23 the current flows through the lead 99 to the switch 2| and from the switch 2| through the lead 98 to the solenoid 22, and through the lead 9| to one side of the primary winding 92 of a transformer 93. The other side of the winding 92 is connected to the negative side 94 of the line by the lead 95. From the solenoid 22 the current flows through the lead 96 to the negative side 94 of the line. The electric ignition element I8 is connected to the secondary winding 96 of the transformer 93 by the leads 9'! and 98. The electric ignition element I8 and the solenoid 22 are now both energized. The energizing of the ignition element I8 renders it operable to ignite the pilot burner I6 as soon as gas is supplied thereto, and the energization of the solenoid 22 causes it, through the line 13 and yoke 12, to shift the various parts of the safety control mechanism from the position shown in Fig. 2 to the position shown in Fig. 3. In this position the valve disc 48 is held away from the valve seat 39 and the metal disc 49 is held against the ends of the legs of the magnet by the stem 62 acting against the resistance of the spring 50. This allows gas to flow from the chamber 36 into the bore 38 and thence through the port 69 and conduit I! to the pilot burner I6 where it is ignited by the ignition element I8. But the gas cannot yet flow to the main burner I since the valve disc 65 is being held against the seat 40 by the spring 66 which cuts off communication between the bore 38 and the chamber 31. As soon as the pilot burner I6 is ignited it projects a flame against and heats both the thermocouple 20 and the thermostatic element I9. The heating of the thermocouple 29 generates a minute current of the order of .009 to .017 volt which energizes the electromagnet 5| sufiiciently for it to hold the metal disc 49 and the stem 46 and valve disc 48 secured thereto in the position shown in Fig. 3 against the pressure of the spring 50 after the disc 49 has been moved into engagement with the magnet 5| by the solenoid 22. But the magnet 5| when energized by the thermocouple 28 is not strong enough to attract and withdraw the metal disc 49, and the stem 46 and valve disc 48 secured thereto, from the position shown in Fig. 2 to the position shown in Fig. 3. It can only hold these parts in this position after they have been moved thereto by the solenoid 22 through the medium of the link 13, yoke 12, plunger 59 and stem 62. The electric circuit between the thermocouple 29 and the winding 54 of the magnet 5| is through the copper tube 28 and the wire 29. This circuit will be maintained as long as the thermocouple is heated. After the thermostatic element I9 has been heated sufficiently, which is after the thermocouple has energized the magnet 5|, it will open the normally closed switch 2 I, breaking the circuit to and de-energizing both the ignition element I8 and the solenoid 22. After the pilot burner has been ignited there is no further need to maintain the ignition element energized. As soon as the solenoid 22 is de-energized the spring 61 will return the plunger 59, stem 62 and valve disc 65 back from the position shown in Fig. 3 to the position shown in Fig. 2 against a pressure of the spring 66. The valve disc 48 will be held in the position shown in Fig. 3 by the magnet 5|. Communication is then established between the chamber 36 and 31 through the bore 38. Gas will then flow from the chamber 36 into the chamber 31 through the bore 38. From the chamber 31 gas will flow through the oven temperature control valve 6 and conduit 3 to the main burner I where it will be ignited by the pilot burner I6. The apparatus is now operating normally, and in the absence of any abnormal conditions it will continue to do so provided the pilot burner remains ignited, until the supply of gas to both the pilot burner and the main burner is cut off by the manual closing of the main control valve 4.

In the event the pilot burner I6 is extinguished for any reason during operation, the thermocouple 29 will cool in a few seconds and de-energize the magnet 5|. The de-energizing of the magnet 5| will allow the spring 50 to move the valve disc 48 back into engagement with the valve seat 39, as shown in Fig. 2, which will cut off the flow of gas from the chamber 36 into the bore 38 and chamber 31, and from them to the pilot light I6 and the main burner I. The burner I will then be extinguished along with the pilot burner. As soon as the thermostatic element I9 cools it will close the switch 2| which will energize both the ignition element I8 and the solenoid 22, as previously described, since the main control valve 4 is still open and the switch 23 is closed. The pilot smears burner- $1 6 will :then r bare-ignited and the rest of the apparatus will again function as described, provided there is gas available. If no gas is available everything will remain in condition to ignite thepilot burner and re-initiate operation assoon as :gas is again available In the event of either a momentary or prolonged power failure during operation, the apparatus will continue to operate normally .until terminated by the manual closing of themain control valve,provided of course that all otlier conditions are normal. In order to operate the apparatus during a prolonged power failure which occurred prior to operation, it is only necessary to hold a match to the pilot burner l6 and manually move the plunger 59 from the position shown in Fig. 2 to the position shown in Fig. 3 and hold it'in this position a sufficient time for the thermocouple 20 to become heated, after which the plunger 59 may be released and'allowed to be returned to its initial position by the spring 61; The apparatus will then continue'to function normally as described, under the control of the pilot burner i6 and "the oven temperature control valve 6.

When 'the apparatus is used in conjunction with the timecontrol mechanism 88 the time control mechanism is set to initiate operation of the main burner l ata predetermined time and to terminate operation thereof at a predetermined later time. The setting of the time control mechanism '80 opens the switches 82 and 83, as shown in Fig. 5. Operating current is supplied to the time control mechanism from the line 81-94 by the leads 99 and Hill. After the time control mechanism 'hasbeen set the main control valve 4 is manually opened in a counterclockwise direction which close the master switch 25. Then at the predetermined set time the time control mechanism will close the switch 82. Current will then flow from positive side 8'! of the line through the leads 88 and Hi-l to the switch 2d. From the switch 24 the current will flow through the lead I02 to the switch 82 and from the switch 82 to the normally closed switch 2| through the leads 103 and 89. From the switch 2! the current will flow back to the negative side 94 of the line and energize the electric ignition element l9 and solenoid 22, as previously described. The main burner I will then operate under the control of the pilot burner I6 and oven temperature control valve 5, as previously described, until its operation is terminated by the simultaneous opening of the switch 32 and the momentary closing of the switch 83 by the clock 8 i.

The switch 83 is interposed in a quinching circuit which includes the leads I95 and E95 and the secondary winding I01 of a transformer N8, the primary winding Hit of which is connected to the line 8194 by the leads Hi3 and ill. One end of the lead 105 is connected to the tube 28 in the thermocouple circuit and the other end thereof is connected to one side of the secondary winding IN; and one end of the lead Hit is connected to the wire 29 of the thermocouple circuit and the other end thereof is connected to the other side of the secondary winding Ifl'i. When the switch 83 is closed the current in the quinching circuit will damp out the thermocouple circuit and de-energize the electromagnet The electromagnet 5| will then release the valve 43 and it will be closed by the spring 50, cutting off the flow of gas to both the main burner and the pilot burner and terminating operation. The thermostatic element will then cool and close the switch it, setting the mechanism in condition for 1D futureiuse. After the main and pilot burners have been extinguished in this manner they cannot be automatically re-ignited, as in the case of the accidental extinguishment of the pilot burner, .duetto the fact that the switch 82 is being held-open by the time control mechanism. After operation has been automatically terminated by the time control mechanism the main control valve may be manually turned oif at any time.

From the foregoing'it will be apparent to those skilled in this art that I have provided a very simple and efficient mechanism for-accomplishing the obj ectsof "theii'nvention.

It:is to beiunderstood that I am not limited to the specific construction shown and described as various modifications canbe made thereto within the scope of the; appended claims.

What is claimed is:

1. -In an automatic ignition and control apparatus of the character described, the combination of a main burner, a pilot burner by which said main burner is ignited, a conduit through which gas is supplied to said main burner, a branch conduit through which gas is supplied to said pilot burner, a normally closed valve interposed in said conduit and operative when closed to cutoff the flow of gas through said conduit and said branch conduit, a solenoid operative when energized to move said valve to open position, an electromagnet operative when energized to hold said valve in open position after said solenoid has been deenergized, a thermocouple mounted in position to be heated by said'pilot burner, athermocouple circuit between said thermocouple and said elec-' tromagnet, said thermocouple being operative when heated to energize said electromagnet through said thermocouple circuit, a quinching circuit hooked into said thermocouple circuit, :a normally open-switch in said quinching circuit, and a time controlmechanism operative to close said switch at a predetermined set time, said quinehing circuit being operative when said switch is closed to dampout said thermocouple circuit and de-energize said electromagnet.

2. In a burner control apparatus of the character described, the combination of a main burner, a pilot burner by which said main burner is ignited, a conduit through which gaseous fuel is supplied to said main burner, a safety control mechanism operative to control the supply of fuel to said main burner interposed in said conduit, a solenoid and operative connections between said solenoid and said safety control valve mechanism, a thermocouple disposed adjacent said pilot burner in position to be heated thereby, a thermocouple circuit between said thermocouple and said safety control mechanism, said solenoid being operative when energized to set said safety control valve mechanism in condition to supply fuel to said main burner and said thermocouple being operative through said thermocouple circuit when heated to maintain said safety control mechanism in said set condition, means operable to control the energization of said solenoid, a quinching circuit hooked into said thermocouple circuit, a normally open switch in said circuit, a time control mechanism, operative connections between said time control mechanism 7 and said means by which said means is actuated at a predetermined time by said time control mechanism to energize said solenoid, operative connections between said switch and said time control mechanism by which said switch is closed at a predetermined time by said time control mechanism, said quinching circuit being operative when said switch is closed to damp out said thermocouple circuit and render said thermocouple ineffective to maintain said safety control mechanism in said set condition.

3. In a burner control apparatus of the character described, the combination of a main burner, a pilot burner by which said main burner is ignited, a conduit through which gaseous fuel is supplied to said main burner, a safety control mechanism operative to control the supply of fuel to said main burner interposed in said conduit, a solenoid and operative connections between said solenoid. and said safety control mechanism, an electromagnet incorporated in said safety control valve mechanism, a thermocouple disposed adjacent said pilot burner in position to be heated thereby and an electric circuit between said thermocouple and said electromagnet, said solenoid being operative when energized to set said safety control valve mechanism in condition to supply fuel to said main burner, said electromagnet being operative when energized to maintain said safety control valve mechanism in said set condition and said thermocouple being operative to energize said electromagnet, means operable to control the energization'of said solenoid, a quinching circuit hooked into said electric circuit, a normally open switch in said quinching circuit, a time control mechanism, operative connection between said time control mechanism and said means by which said means is actuated at a predetermined set time by said time control mechanism to energize er, a pilot burner by which said main burner is ignited, a conduit through which gaseous fuel is supplied to said main burner, a safety control mechanism operative to control the supply of fuel to said main burner interposed in said conduit, a solenoid and operative connections between said solenoid and said safety control mechanism, an electromagnet incorporated in said safety control mechanism, said solenoid being operative when energized to set said safety control mechanism in condition to supply fuel to said main burner and said electromagnet being operative when energized to maintain said safety control valve mechanism in said set condition, means operable to control the energization of said solenoid, an electric circuit operative to energize said electromagnet, a quinching circuit hooked into said electric circuit, a normally open switch in said quinching circuit, a time control mechanism, operative connections between said time control mechanism and said means by which said means is actuated at a predetermined set time by said time control mechanism to energize said solenoid, operative connections between said time control mechanism and said switch by which said switch is closed at a predetermined set time by said time control mechanism, said quinching circuit being operative when said switch is closed to damp out said electric circuit and de-energize said electromagnet.

5. The burner control apparatus as set forth in claim 4 in which said means includes a normally open switch and a normally closed switch disposed in series with each other.

6. The burner control apparatus as set forth in claim 5 in which said normally closed switch is operatively connected to a thermostatic element for actuation thereby, and said thermostatic element being disposed adjacent said pilot burner in position to be heated thereby.

CHARLES M. MAYER.

No references cited. 

